Epidemiology and chemotherapy of parasitic infections in wild omnivores in the Mahendra Choudhury Zoological Park , Chhat Bir , Punjab

The present investigation deals with the occurrence and intensity of gastrointestinal helminthic infections along with chemotherapeutic response in 13 different omnivore species belonging to Primate, Ursidae, Suidae and Viverridae at M.C Zoological Park, Chhatbir in Punjab, India. The overall occurrence of gastrointestinal parasites based on copro-parasitoscopic analysis (CPS) of 317 samples for helmithic eggs was found to be 29.02 per cent. The various parasitic eggs detected were Trichuris spp, Hymenolepis diminuta, Strongyloides spp, Ascaris suum and Ascaris spp. The most common parasitic infection found in omnivores specially the primates was of Trichuris spp. (86.96%). Mixed infection of Trichuris spp. and H. diminuta was recorded in assamese monkeys with highest intensity of Trichuris spp. The EPG for Trichuris spp varied from 1800-7500. The EPG ranging from 100-750 was recorded for H. diminuta and Strongyloides spp which was followed by that of Trichuris spp. in rhesus monkeys, Ascaris suum in wild boar, Trichuris spp in capped langur, Trichuris spp in common langur, and Ascaris spp. in sloth bear. In assamese monkeys the infection was concurrent to tuberculosis. Treatment of animals with appropriate drug based on the species of parasites present was found to be 100 per cent effective as indicated by faecal egg count reduction test which reached zero level 5-30 days post treatment. There was no re-occurrence of parasitic infection till day 55 post treatment.

The presence of as many as 150 recognized zoonotic diseases of infectious origin in wild animals maintained under a single facility in a zoo always poses a risk for domestic animals as well as man in its periphery and vice-versa (Acha & Szyfres 1987).Parasitic diseases of wildlife are still in infancy in India and data are still on the base line (Islam 2006).These diseases constitute one of the major problems in management causing mortality and morbidity in wild animals in captivity (Rao & Acharjyo 1984).Little work has been done to understand the epidemiology of different parasitic diseases in wild animals kept in Indian zoos (Goswami et al. 1994;Goswami & Chakraborty 1996;Chhangani et al. 2001;Kumar et al. 2005;Singh et al. 2006).Parasites can affect host survival and reproduction directly through pathological effects (blood loss, tissue damage, spontaneous abortion, congenital malformations and death) and indirectly by reducing host condition.Through these proximate mechanisms, parasites can potentially regulate host populations (Gregory & Hudson 2000;Hochachka & Dhondt 2000).
Keeping in view the importance of parasitic infections in wild omnivores and their potential for transmission to domestic animals and man, this study was conducted to investigate the occurrence of various gastrointestinal parasitic infestations in various species of omnivores alongwith their chemotherapeutic control at the Mahendra Choudhury Zoological Park, Chhat Bir in Punjab (29 0 49-30 0 47N & 75 0 58-76 0 54E) India.

Materials and Methods
Three-hundred-and-seventeen fresh faecal samples of 13 different omnivore species belonging to Primates, Ursidae, Suidae and Viverridae were collected over a period of six months to know the occurrence and intensity of gastrointestinal parasitism.The samples from the enclosures in which animals were housed in groups were pooled together, and individual faecal samples were taken from animals kept singly.Regular Copro-parasitoscopic analysis (CPS) was done using standard qualitative (sedimentation and floatation) and quantitative tests (Mc Master counting technique) (Soulsby 1982).An arbitrary designation was assigned to denote the intensity of infection as done by Nashiruddullah & Chakraborty (2001).One part of the faecal sample was preserved in 10% formalin for proper analysis, identification, micrometric analysis and microphotography.The identification of eggs was based on the morphology and the micrometric studies (Bowman 1999).
To see the chemotherapeutic response of appropriate drugs, animals were divided into three species groups, sex, age, type of enclosure and the type of parasitic infection (single or mixed) found in these animals (Table 2).The drug was given at a slightly high dosage so as to cover up the wastage of drug when given mixed in feed.The EPG was calculated on day 0, i.e., before treatment and days 1, 2, 3, 5, 7, 15, 30 and 55 post treatment (DPT) to record the reduction or re-occurrence of parasitic infection.The percent reduction in the faecal egg count after treatment was calculated to know the efficacy of the drug used.

Results and Discussion
Out of 317 samples taken from 13 different omnivore species, 92 were found to be positive for helminthic eggs giving a prevalence of 29.02%.Species-wise prevalence is given in Table 1 and Image 1.The parasite load was more in the animals kept in large groups suggesting transmission of infection from one animal to another whereas animals kept in isolation or small groups were relatively free or had less infection.

Intensity of parasitic infections
Highest intensity of infection was in Assamese Macaques with mean EPGs ranging between 100-7500 for various parasites, viz., Trichuris spp., H. diminuta and Strongyloides spp.followed by Rhesus Macaques Macaca mulatta for Trichuris spp., Wild Boar Sus scrofa for A. suum, Capped Langur Trachypithecus pileatus for Trichuris spp., Common Langur Semnopithecus sp. for Trichuris spp., and Sloth Bear Melursus ursinus for Ascaris spp.(Table 1).The intensity of infection among primates was more in Assamese Macaques than other primates as they were kept overcrowded in cages.These animals were undergoing treatment for tuberculosis, so the parasitic infection in these animals was concurrent to tuberculosis which made them more prone to infection than other primates.The humidity in the cages of the Assamese Macaques was comparatively higher as there was less access to direct sunlight.
Based on morphology and the micrometric reading (Soulsby 1982) OPEN ACCESS | FREE DOWNLOAD the eggs of Trichuris spp.detected in Assamese Macaques, Rhesus Macaques, Capped Langur and Common Langur were found comparable to those of Trichuris trichuria.Eggs of H. diminuta were also detected in Assamese Macaques as per morphology and micrometric study (Bowman 1999).Similarly Ascaris suum eggs were identified in Wild Boars.

Therapeutic Studies
The animals of group I (Assamese Macaques 31(11 adult females + 9 young ones +11 adult males)) having mixed parasitic infection  with Trichuris spp.and H. diminuta were housed together in an enclosure.The animals were treated with Prazital ® tablets (each tab having praziquantal-50mg, pyrantal pamoate-144mg and fenbendazole 150mg; Ranbaxy India Ltd.) @ 1.5 tablets/animal x 3days mixed in feed.The results revealed that reduction in faecal egg count for Trichuris spp.and H. diminuta was 72.68% and 93.47% on day one post treatment and 99.25% and 100.00% on day 5 post treatment, respectively (Table 2).There was no re-occurrence of infection till 55 DPT, so the drug was found to be highly efficacious in limiting these parasitic infections in Assamese Macaques.
The animals of group II (Rhesus Macaques) had single Trichuris spp.infection.This group was further subdivided into 2 subgroups.Subgroup 1 constituted of 6 adult males and Subgroup 2 of 3 females and 4 young ones.Both subgroups were treated with pyrantal pamoate (Tab Nemocid ® 250mg each; IPCA) @15mg.kg - body weight mixed in feed as a single dose treatment.The reduction in faecal egg count was 95% and 92.85% for subgroup 1 and subgroup 2 on day two post treatment and was 100% and 94.29% on day 5 post treatment, respectively.In subgroup 2, the reduction in faecal egg count was 100% by 15DPT and it was seen that there was no recurence of infection till 55DPT (Table 2).
The animals in group III (two Wild Boars) had a single A. suum infection.The animals were treated with pyrantal pamoate (Tab Nemocid 250mg each; ICPA) @ 15mg.kg -1 body weight in feed.The reduction in faecal egg count was 66.04% by day one post treatment, 77.36% by 2DPT and 100% by 3DPT (Table 2).There was no recurence of infection till 30DPT.It was concluded that pyrantal pamoate was 100% effective in eliminating the infection of Ascaris suum from Wild Boars.
It was observed that regular faecal examination for parasitic ova/ larva along with assessment of parasitic load and administration of desired anthelmintics, when warranted, at regular intervals would be able to curtail parasitic infection.Quarantine measures for parasitic disease control need to be standardized in Indian zoos.Chakraborty (1991) opined that the infection with the parasites having a direct life cycle is common while those having indirect life cycle occur rarely in their natural hosts in captivity as the chances of transmission are reduced when intermediate hosts have little chance to come in contact with animals.

Table 1 . Mean micrometric readings of eggs and intensity of parasitic infections
* Trichuris spp and Hymenolepis diminuta